The conversion of atmospheric carbon dioxide and sunlight into energy-rich carbohydrates through photosynthesis is one of the most fundamental processes on Earth - and one on which we all depend.

Information from FLEX will improve our understanding of the way carbon moves between plants and the atmosphere and how photosynthesis affects the carbon and water cycles.

In addition, information from FLEX will lead to better insight into plant health and stress. This is of particular relevance since the growing global population is placing increasing demands on the production of food and animal feed.

Although most people have heard of photosynthesis, the process involves an extremely complex chain of events.

Working in sequence, there are two different 'solar power systems' inside plant and algae cells. They collect energy in sunlight and produce chemical energy for photosynthesis, heat and a faint fluorescence, subject to environmental conditions and the health of the plant.

So far, it has not been possible to measure photosynthetic activity from space, but FLEX's novel fluorescence imaging spectrometer will observe this faint glow, which serves as an indicator of photosynthesis.

The FLEX satellite will orbit in tandem with one of the Copernicus Sentinel-3 satellites, taking advantage of its optical and thermal sensors to provide an integrated package of measurements.

Jan Woerner, ESA's Director General, said, "FLEX will give us new information on the actual productivity of vegetation that can be used to support agricultural management and the development of a sustainable bioeconomy. It will therefore help to understand our ecosystem."

"With the selection of the FLEX mission, ESA Member States have continued to show their determination to provide essential data to the scientific community to better understand our planet while at the same time serving society."

Volker Liebig, ESA's Director of Earth Observation Programmes, added, "The selection of FLEX is an important milestone in our series of Earth Explorer missions.

"FLEX will give us a better understanding of an important part of the carbon cycle and provide important information about the health and stress of the planet's vegetation.

"Through this, FLEX might make a contribution to the understanding of feeding the increasing population of our planet."

The planned launch date for the FLEX mission is in 2022.

About ESA's Earth Explorers

The Earth Explorers are a series of satellites developed to further our understanding of Earth. Three missions in orbit are providing new insight into Earth's cryosphere, soil moisture and ocean salinity, and the magnetic field. Future Explorer missions will provide new insight on wind, clouds and aerosol impact on the radiation budget, and global forest biomass.

About the European Space Agency

The European Space Agency (ESA) provides Europe's gateway to space.

ESA is an intergovernmental organisation, created in 1975, with the mission to shape the development of Europe's space capability and ensure that investment in space delivers benefits to the citizens of Europe and the world.

ESA has 22 Member States: Austria, Belgium, the Czech Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Ireland, Italy, Luxembourg, the Netherlands, Norway, Poland, Portugal, Romania, Spain, Sweden, Switzerland and the United Kingdom, of whom 20 are Member States of the EU.

ESA has established formal cooperation with seven other Member States of the EU. Canada takes part in some ESA programmes under a Cooperation Agreement.

By coordinating the financial and intellectual resources of its members, ESA can undertake programmes and activities far beyond the scope of any single European country. It is working in particular with the EU on implementing the Galileo and Copernicus programmes.

ESA develops the launchers, spacecraft and ground facilities needed to keep Europe at the forefront of global space activities.

Today, it develops and launches satellites for Earth observation, navigation, telecommunications and astronomy, sends probes to the far reaches of the Solar System and cooperates in the human exploration of space.